GALAXY OF TOOLS

DATES SECTOR · 21 TOOLS

Free Date & Time Tools Online

Ages, date differences, time zones, timers and countdowns. 21 free tools, no sign-up.

Age CalculatorFind your exact age in years, months and days, plus your next birthday, birth weekday and zodiac signs.Date & TimeTime Zone ConverterConvert a date and time across time zones — with daylight saving, half-hour zones and a meeting planner.Date & TimeDate Difference CalculatorCount the days between two dates, with years, months, weeks, hours and business days.Date & TimeCountdown TimerA big online timer with alarm sound, presets and fullscreen — or count down to any date and share it.Date & TimeStopwatchA precise online stopwatch with lap times, splits, keyboard shortcuts and CSV export.Date & TimeDate CalculatorAdd or subtract days, weeks, months, years or business days from any date and get the exact result.Date & TimeAlarm ClockSet one or more alarms with repeat days, four built-in sounds, volume control and snooze — right in your browser.Date & TimeTime Duration CalculatorWork out the time between two clock times — overnight too — and add or subtract a list of durations.Date & TimeWorld ClockLive clocks for the cities you care about, with UTC offsets, time differences and day or night at a glance.Date & TimeBusiness Days CalculatorCount working days between two dates, or add business days to a date — with your own weekends and holidays.Date & TimeCalendar GeneratorPrintable month or year calendar with week numbers, notes, Indian festivals, US holidays or Hijri dates.Date & TimeBig Digital Day ClockA very large, high-contrast clock showing the day of the week, date, time and part of the day, full screen.Date & TimeDay of the Week CalculatorFind the weekday of any date in history or the future — with the Doomsday rule and Zeller’s formula worked out.Date & TimeZodiac Sign CalculatorFind your Western star sign from your birth date, with exact cusp answers, element, modality and ruling planet.Date & TimeHours CalculatorFill in a weekly time card to total hours worked, overtime and gross pay — breaks and night shifts included.Date & TimeSunrise Sunset CalculatorSunrise, sunset, solar noon, day length, golden hour and twilight times for any city, coordinates or date.Date & TimeWeek Number CalculatorFind the week number of any date, the dates of any week, and every week of a year — ISO 8601 or US style.Date & TimeChinese Zodiac CalculatorFind your Chinese zodiac animal and element from your exact birth date, using real Lunar New Year dates 1900–2100.Date & TimeLeap Year CheckerCheck whether any year is a leap year, see the rule worked out, and list every leap year in a range.Date & TimeBirthstone FinderFind the birthstone for any month on the modern, traditional and UK lists, with colours, hardness and a gift note.Date & TimeUnix Timestamp ConverterConvert epoch time to a readable date in any time zone, and dates back to Unix seconds or milliseconds.Date & Time

Dates, ages, time zones and timers in one place

Counting days on a paper calendar is slow and easy to get wrong, especially across month ends, leap years and time zones. These free date and time tools do it precisely. The age calculator gives your exact age in years, months and days, the date difference calculator counts the days between any two dates, and the date calculator adds or subtracts days, weeks, months or years from a date you choose.

For work across borders, the time zone converter handles daylight saving and half-hour offsets such as India’s UTC+5:30, and the world clock keeps several cities in view at once. For deadlines and payroll, the business days calculator skips weekends and the holidays you choose, and the hours calculator totals a weekly time card with breaks and overtime. Live tools, including a countdown timer, a stopwatch and an alarm clock, run right in the browser tab.

HR teams use them for notice periods and leave balances, students for exam countdowns, freelancers for billing hours, travellers for flight times and families for planning calls with relatives on other continents. Everything is calculated on your device from its clock and the browser’s built-in time zone rules, so nothing you enter is sent anywhere. There is no sign-up, and the tools work the same on a phone as on a desktop. Each one explains the rule it follows, such as ISO 8601 week numbering or the Gregorian leap-year rule, so you can check the answer yourself.

Picking the right date tool

  • Date difference or date calculator. If you know both dates and want the gap, use date difference. If you know a start date and a gap, such as “90 days from today”, use the date calculator.
  • Calendar days or business days. Notice periods, visa stays and interest periods usually count calendar days, while delivery estimates and payment terms often count working days. Check which one your rule uses before you count.
  • Time duration or hours calculator. Time duration finds the gap between two clock times, including overnight shifts. The hours calculator adds up a full week of start and end times, breaks and overtime.
  • Unix time. Developers can turn epoch seconds or milliseconds from logs and APIs into readable dates with the Unix timestamp converter.

Getting dates right

Small conventions cause most date mistakes. Keep these in mind:

  • Decide whether to include the end date. Monday to Friday is four days apart, but five days if you count both ends, which many contracts and leave policies do.
  • Week numbers depend on the convention. ISO 8601, used across Europe and much of Asia, starts weeks on Monday and week 1 contains the first Thursday of the year; US-style numbering starts on Sunday. The week number calculator supports both.
  • When scheduling a call, convert the time for every participant and check the date too: a 9 pm meeting in New York is already the next morning in Mumbai.
  • Leap years add 29 February every four years, except century years not divisible by 400, so 2000 was a leap year and 2100 will not be.
  • For focused work sessions with breaks, the Pomodoro timer in our productivity tools is a better fit than a plain countdown.

Date & Time: frequently asked questions

How do I calculate my exact age?

Enter your date of birth in the age calculator. It counts complete years, then the remaining months and days, handling different month lengths and leap years correctly.

How many days are there between two dates?

Subtract the earlier date from the later one using each month’s real length. The date difference calculator does this instantly, can include the end date, and also shows the gap in weeks and business days.

Does the time zone converter handle daylight saving time?

Yes. It uses the time zone rules built into your browser, so clocks change on the correct dates for each place, including the different start dates in the US, the UK and Europe.

What is a Unix timestamp?

It is the number of seconds since 00:00:00 UTC on 1 January 1970, ignoring leap seconds. Many systems store it in milliseconds instead, which gives a 13-digit number rather than a 10-digit one.

Will the countdown timer keep time if I switch tabs?

Yes, as long as the tab stays open and your device does not go to sleep. The timers measure real elapsed time from the clock, so they stay accurate even when the browser slows background tabs.

How many working days are in a year?

A year has 260 to 262 weekdays, depending on the year and the day it starts on. Subtract your public and company holidays to get working days; the business days calculator does this with your own holiday list.